Hollow core fiber laser system, apparatus, and method

Abstract

An optical system, apparatus, or method can comprise or implement a seed module to generate and output electromagnetic radiation at a predetermined amplitude and at a predetermined wavelength. The seed module can include at least one non-hollow core optical fiber and at least one hollow core optical fiber. One at least one non-hollow core optical fiber can be optically coupled to one at least one hollow core optical fiber. The non-hollow core optical fiber and the hollow core optical fiber may receive and pass electromagnetic radiation emitted from a laser diode or amplifier.

The invention claimed is: 
     
       1. An optical system, comprising:
 a seed module configured to generate and output electromagnetic radiation at a second predetermined amplitude and at a second predetermined wavelength, the seed module including:
 a laser diode configured to emit electromagnetic radiation having a first predetermined amplitude and a first predetermined wavelength, 
 a pump signal combiner configured to couple the electromagnetic radiation from the laser diode and electromagnetic radiation circulated through the seed module, 
 a gain fiber including an input, an output, a doped core extending a length of the gain fiber, and a third cladding layer surrounding the doped core, and configured to guide electromagnetic radiation coupled into the doped core from the pump signal combiner, 
 a first non-hollow core optical fiber configured to guide electromagnetic radiation, the first non-hollow core optical fiber having a first cladding layer surrounding a solid core medium extending a length of the first non-hollow core optical fiber, 
 a first hollow core optical fiber configured to guide electromagnetic radiation, the first hollow core optical fiber having a second cladding layer surrounding a hollow core of the first hollow core optical fiber that extends a length of the first hollow core optical fiber, 
 a fiber coupler that couples the first non-hollow core optical fiber to the first hollow core optical fiber so as to pass electromagnetic radiation from the first non-hollow core optical fiber to the first hollow core optical fiber, 
 a second hollow core optical fiber configured to guide electromagnetic radiation, the second hollow core optical fiber having the second cladding layer surrounding a hollow core of the second hollow core optical fiber that extends a length of the second hollow core optical fiber, and 
 a feedback hollow core optical fiber configured to feedback electromagnetic radiation at an output of the seed module to the pump signal combiner; and 
 
 an output hollow core optical fiber optically coupled to the seed module and configured to output electromagnetic radiation to outside the seed module. 
 
     
     
       2. The optical system of  claim 1 ,
 wherein the gain fiber is configured to generate a laser beam at the output thereof based on the electromagnetic radiation coupled into the gain fiber at the input thereof, and 
 wherein the fiber coupler is configured to receive the laser beam at an input thereof and guide the laser beam into the first hollow core optical fiber or the second hollow core optical fiber. 
 
     
     
       3. The optical system of  claim 1 , wherein a range of the second predetermined wavelength of the electromagnetic radiation the seed module generates and outputs is 190 nm to 10,000 nm. 
     
     
       4. The optical system of  claim 1 , wherein the seed module is configured to emit electromagnetic radiation having an average optical power output of 1 mW to 10 kW. 
     
     
       5. The optical system of  claim 1 , wherein the seed module is a multimode laser. 
     
     
       6. The optical system of  claim 1 , wherein the doped core of the gain fiber is configured to provide gain to the electromagnetic radiation coupled into the gain fiber via interaction with doping ions in the doped core. 
     
     
       7. The optical system of  claim 1 , further comprising an optical isolator configured to direct electromagnetic radiation in a predetermined direction,
 wherein the laser diode is configured to forward pump, and 
 wherein the fiber coupler is optically coupled to the optical isolator by a third hollow core optical fiber. 
 
     
     
       8. The optical system of  claim 7 , further comprising an optical fiber tap configured to monitor and adjust electromagnetic radiation received from the optical isolator,
 wherein the optical isolator is optically coupled to the optical fiber tap by a fourth hollow core optical fiber. 
 
     
     
       9. The optical system of  claim 7 , wherein the optical isolator is configured to emit the electromagnetic radiation to outside the seed module. 
     
     
       10. The optical system of  claim 8 , further comprising an output fiber coupler configured to split received electromagnetic radiation,
 wherein a first portion of the split electromagnetic radiation is emitted to outside the seed module, and 
 wherein a second portion of the split electromagnetic radiation is circulated back to the pump signal combiner. 
 
     
     
       11. The optical system of  claim 10 , wherein the seed module is a ring cavity laser. 
     
     
       12. The optical system of  claim 1 , further comprising at least one amplifier, including:
 at least one amplifier optical fiber including an input, an output, and a fourth cladding layer surrounding a solid core medium extending a length of the at least one amplifier optical fiber, 
 an amplifier gain fiber including an input, an output, a doped core extending a length of the amplifier gain fiber, and the third cladding layer surrounding the doped core and configured to guide electromagnetic radiation coupled into the doped core, 
 an amplifier laser diode configured to emit electromagnetic radiation having the second predetermined wavelength at an output thereof, 
 an amplifier pump signal combiner including an input and an output, and configured to couple electromagnetic radiation from the amplifier laser diode and received electromagnetic radiation into the amplifier gain fiber, 
 an amplifier fiber coupler including an input and an output, the amplifier fiber coupler configured to combine electromagnetic radiation received from the at least one amplifier optical fiber at the input thereof and couple the combined electromagnetic radiation to the first or the second hollow core optical fiber at via the output thereof, and 
 an amplifier output fiber configured to guide electromagnetic radiation out to the seed module, 
 wherein the output of the amplifier laser diode is optically coupled to the input of the at least one amplifier optical fiber, 
 wherein the output of the at least one amplifier optical fiber is optically coupled to the input of the amplifier pump signal combiner, 
 wherein the output of the amplifier pump signal combiner is optically coupled to the input of the amplifier gain fiber, 
 wherein the output of the amplifier gain fiber is optically coupled to the input of the amplifier fiber coupler, 
 wherein the output of the amplifier fiber coupler is optically coupled to the input of the second hollow core optical fiber, and 
 wherein the output of the second hollow core optical fiber is optically coupled to the amplifier output fiber. 
 
     
     
       13. The optical system of  claim 12 , wherein the seed module and the at least one amplifier are optically coupled by the second hollow core optical fiber. 
     
     
       14. The optical system of  claim 1 , wherein the second hollow core optical fiber is the output hollow core optical fiber that is configured to output electromagnetic radiation to outside the seed module. 
     
     
       15. The optical system of  claim 1 , wherein the first predetermined wavelength generated by the laser diode is a pumping wavelength. 
     
     
       16. The optical system of  claim 1 , wherein the second predetermined wavelength generated by the seed module is a lasing wavelength. 
     
     
       17. An optical system, comprising:
 a seed module configured to generate and output electromagnetic radiation at a second predetermined amplitude and at a second predetermined wavelength, the seed module including:
 a laser diode configured to emit electromagnetic radiation having a first predetermined amplitude and a first predetermined wavelength, 
 a hollow core optical fiber configured to guide electromagnetic radiation, the first hollow core optical fiber having a first cladding layer surrounding a hollow core extending a length of the hollow core optical fiber, and 
 a gain fiber including an input, an output, a first doped core extending a length of the gain fiber, and a second cladding layer surrounding the first doped core, and configured to guide electromagnetic radiation coupled into the first doped core from a pump signal combiner; and 
 
 an amplifier configured to output electromagnetic radiation at the second predetermined amplitude and the second predetermined wavelength, the amplifier including:
 an amplifier gain fiber including an input, an output, and a second doped core, the second doped core extending a length of the amplifier gain fiber, and a third cladding layer surrounding the second doped core and configured to guide electromagnetic radiation coupled into the second doped core, and 
 an amplifier laser diode configured to emit electromagnetic radiation having the second predetermined wavelength at an output thereof, 
 
 wherein the seed module is optically coupled to the amplifier by the hollow core optical fiber, and 
 wherein the output of the gain fiber is optically coupled to the hollow core optical fiber, and the electromagnetic radiation produced from the gain fiber is emitted by the seed module and directed to the amplifier by the hollow core optical fiber. 
 
     
     
       18. The optical system of  claim 17 , wherein the seed module further includes an optical isolator configured to emit electromagnetic radiation out of the seed module. 
     
     
       19. The optical system of  claim 17 , further comprising an output fiber coupler configured to split received electromagnetic radiation such that a first portion of the split electromagnetic radiation is emitted out of the seed module and a second portion of the split electromagnetic radiation is circulated back to a pump signal combiner of the seed module. 
     
     
       20. A seed module comprising:
 a first hollow core optical fiber having a first cladding layer surrounding a hollow core extending a length of the first hollow core optical fiber, the first hollow core optical fiber optically coupling a laser diode configured to emit electromagnetic radiation having a first predetermined amplitude and a first predetermined wavelength; 
 a gain fiber including a doped core extending a length of the gain fiber; 
 a fiber coupler; 
 a first non-hollow core optical fiber; and 
 an output hollow core optical fiber optically coupled to an output of the first hollow core optical fiber and configured to output electromagnetic radiation to outside the seed module, 
 wherein the seed module is configured to generate and output electromagnetic radiation at a second predetermined amplitude and at a second predetermined wavelength based on the electromagnetic radiation having the first predetermined amplitude and the first predetermined wavelength.